The word leapfrogging is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 26
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (46 words)
aileron, aligner, eloping, fearing, finagle, firepan, flagger, flaring, flogger, foaling, foggier, fogging, foliage, foreign, forging, fragile, gaoling, gearing, giggler, glaring, goaling, golfing, gorging, groping, ironage, lagging, leafing, leaping, learing, legging, loafing, logging, niggler, opaline, parging, pealing, pergola, pingler, plainer, praline, profane, profile, proline, ragging, realign, reaping